It might also make sense for the communications officer to be able to field strip a phaser rifle blindfolded and calculate how to do the Kessel Run in less than twelve parsecs, but that doesn't mean either of those skillsets have anything more to do with being a communications officer than being a skilled linguist.
Let me put this as simply as possible.
A linguist is someone who studies languages. How they evolve, the mechanics, etc., etc.
The communications officer is in charge of operating and maintaining the ship's communications gear, keeping up with official codes and protocols, and so forth.
The two professions have very little to do with each other.
If anything, the ship's linguist would be in the sciences division, right alongside Lt. Palomas, studying ancient artifacts and analyzing the inscriptions.